Shrinkproofing and improvement in stretch characteristics of wool

ABSTRACT

WOOL IS SHRINKPROOFED BY TREATING IT WITH (1) A WATER SOLUBLE ORGANOPHOSPHORUS COMPOUND OF THE FORMULA R-P(-CH2-OH)2 (I) OR R-P(+)(-CH2-OH)3 X(-) WHERE R IS HYDROGEN, ALKYL OR ALKENYL AND X IS AN ANION IN FORMULA II OR THE WOOL IS TREATED WITH THE PHOSPHOROUS OXIDE OF A COMPOUND OF FORMULA I AND (2) MELAMINE; A WATER SOLUBLE ALKYL ETHER OF METHYLOL MELAMINE OR METHYLOLMELAMINE. THEN THE WOOL IS WASHED WITH AN ALKALINE SOLUTION TO IMPART STRETCH CHARACTERISTICS.

Oct. 10, 1972 H. R. RICHARDS SHRINKPROOFING AND IMPROVEMENT IN STRETCH CHARACTERISTICS OF WOOL 3 Sheets-Sheet 1 Filed July 8, 1969 on oN o d 4 Oct. l0, 1972 H. R. RICHARDS 3,697,219

SHRINKPROOFINC AND IMPROVEMENT 1N STRETCH CHARACTERISTICS 0F wooL Filed July 8, 1969 3 Sheets-Sheet i FIGZ TIME (HR.) SUPERCONTRACTION OF TREATEO FIBERS IN SOAP (0.25%) AND SODIUM CARBONATE (O.25/) SCLUTION AT 22C.

l Q`oo cocr cv O NOILDVBLNODHBdOS Oct. 10, 1972 H. R. RICHARDS SHRINKPROOFING AND IMPROVEMENT IN STRETCH CHARACTERISTICS CF wCoL 3 Sheets-Sheet 5 Filed July 8, 1969 o m 8 2 8 8 o.

United States Patent Officey Patented Oct. 10, 1972 U.S. Cl. 8-127.6 14 Claims ABSTRACT OF THE DISCLOSURE Wool is shrinkproofed by treating it with (1) a water soluble organophosphorus compound of the formula (I) R-P CHzOH CHzOH where R is hydrogen, alkyl or alkenyl and X is an anion in Formula II or the wool is treated with the phosphorous oxide of a compound of Formula I and (2) melamine; a water soluble alkyl ether of methylol melamine or methylolmelamine. Then the wool is -washed with an alkaline solution to impart stretch characteristics.

The present invention relates to the shrinkproofing of wool, i.e. rendering wool resistant to shrinking. In particular, the present invention relates to a process for shrinkproofing wool, such as in the form of fibres, yarns or fabrics, in a simple and economical manner without degradation of the Wool to a significant extent. In a particularly desirable embodiment thereof the present invention relates, in addition to the imparting of improved stretch characteristics to the shrinkproofed wool.

It is known that wool fibre fabrics will shrink and felt during handling or washing unless shrinkproofed. This shrinking and felting is believed to be due to the unusual surface characteristics of the Wool libres, i.e. the overlapping scales ou the wool fibre surface giving a ratchet effect and hence migration and drawing together of the wool libres. Because of this peculiar structure wool fibres exhibit a directional frictional effect (dfe) which causes the interlocking of the scales and fibre travel endows wool with such properties as fulling, felting and shrinking. Therefore, unless wool is given a shrinkproofing treatment, garments will shrink and felt in use or during washing. Thus nearly all wool yarns or fabric are at the present time shrinkproofed by several methods including (l) the deposition of polymers on the surface of the fibres to decrease the ratchet effect of the scales, an example of this treatment being a process known under the trademark Wurlan; (2) treatment of the wool either in solution or in moist fabric form with chlorine and (3) oxidation of the wool with a variety of oxidizing agents. However, all the known shrinkproofing treatments, including those above for Wool, have disadvantages, the chemical treatments tending to degrade the wool fibres to an excessive extent and the resin treatments being difiicult to apply uniformly over the fibre surface.

The present invention provides a process for the simple and economical shrinkprooling of wool which Substantially reduces the aforesaid disadvantages and produces a shrinkproofed ywool with a minimum of degradation there- It has now been found that wool may be readily shrinkproofed, i.e. the directional frictional effect of the Wool libre substantially reduced with a minimum of degradation of the wool by subjecting the wool to treatment with an aqueous solution containing a water soluble hydroxy organophosphorus compound of formula hereinafter defined in a concentration of 0.2 to 2% by weight and a water soluble melamine compound having at least one free hydrogen atom or methylol group attached to each of the amino nitrogen atoms in a concentration of at least 0.5 by weight at a temperature in the range from 40 to C. for a sufiicient time to effect the desired shrinkprooling and usually for a time from 48 hours to 2 minutes.

According to the present invention therefore there is provided a process for shrinkprooflng wool such as Wool fibres, fabrics and yarns, which comprises impregnating said wool, suitably by immersion, with an aqueous solution containing a water soluble hydroxy organo-phosphorus compound having the formula CHQOH CHiOH or (II) CHZOH (I) R-P or a phosphorous oxide of the compound of Formula I and wherein R is hydrogen, alkyl or alkenyl and preferably lower alkyl having 1 to 3 carbon atoms or lower alkenyl having 2 or 3 carbon atoms which lower alkyl and lower alkenyl groups may be substituted by chlorine or hydroxy groups and X in Formula II is an anion such as chloride, bromide, hydroxyl or acetate in a concentration of from 0.2 to 2% by weight and a water soluble melamine compound a concentration of at least 0.5% by weight at a temperature of from 40 C. to 80 C. for a period of time sufficient to effect the desired shrinkproofing.

It is found that at temperatures below about 40 C. the reaction between the organo-phosphorus compound, the cyclic nitrogen compound and the Wool is very Slow and shrinkproofing is unsatisfactory even after 48 hours. At temperatures of above 80 C. the wool is relatively rapidly degraded. Therefore it is essential, to provide an effective shrinkproofing process, that the reaction temperature be within the range 40 to 80 C. and preferably the temperature is in the range 60 to 70 C. The process should be carried out until sufficient shrinkprooling is attained in the wool; the resistance of the wool to shrinking being readily determined by simple experiment. However, it will be readily seen that the lower the temperature the longer the time is required to effect adequate shrinkproofing and thus the times will normally vary from about 48 hours at the lower temperature to 2 minutes at the higher temperature. The optimum conditions have been found to be a temperature of about 65 C. and a period of about l5 minutes.

The concentration of the reactants particularly the organophosphorus compound is critical, the concentration of the hydroxy organo-phosphorus compound is in the range of from 0.2 to 2% by Weight as below 0.2% by weight adequate shrinkproofing of the wool is not readily obtained. At high temperature and above 2% by weight excessive degradation of the wool libres occurs. The maximum concentration of the melamine compound is not critical but it should be present in at least a concentration of 0.5% by weight to obtain significant shrinkproofing and preferably be present in at least the same molar concentration as the hydroxy organo-phosphorus compound.v

More preferably the concentration of each of the reactants is the same and the optimum concentration is about 1% for each of the reactants and this together with a reaction temperature of about 65 C. and a treatment time of about 15 minutes provides optimum shrinkproofng conditions. If higher or lower concentrations of the reactants are used a proportionally shorter or longer times of reaction are required or alternatively lower or higher reaction temperatures are required.

In the above formulae for the hydroxy organo-phosphorus compound Rv is desirably hydrogen, methyl or hydroxymethyl andr particularly suitable hydroxy organophosphorus compounds include tris ('hydroxyrnethyl) phosphine and tetrakis (hydroxymethyl) phosphonium chloride or hydroxide. The compounds of Formula I are relatively unstable in 'air quickly forming oxide's of the formula.

O CHzOH CHzOH. (III) which are also useful in the process of the present invention and are in fact the preferred form of the compounds of Formula I due to their ready solubility in water and their stability. However more preferred are the quaternary salt compounds of Formula II which are readily soluble in water and are stable compounds.

It is essential that the melamine compounds have at least one free. hydrogen atom or methylol group attached to each amino nitrogen atom for it to be reactive in the process of the present invention and provide significant shrinkproofiug. It has been found that other nitrogen containing compounds such as urea are not useful in the process of the present invention. Particular melamine compounds which may be mentioned include melamine mono, di, or tri-methylol melamine or lower alkyl ethers thereof and mono-, di, or tri-alkylated melamines which may be substituted on the amino nitrogen atoms by one, two or three methylol groups.

The water soluble hydroxy organo-:phosphorus compound and the melamine compound are critical to the effective shrinkproofing of wool by the process of the present invention. Thus it is known that if the cystine in wool fibres can be reacted chemically the differential frictional effect of the scales, which as aforesaid is believed to be responsible for shrinkage and felting, is reduced and this differential frictional effect can be further reduced if the tyrosine in wool fibres is reacted at the same time. While the particular part played by cystine and tyrosine in the directional frictional effect of wool fibres is not completely understood it is believed that the scales on the surface of the wool fibres have an appreciable cystine content. Thus while it is known that the disulphide bonds of cystine can be readily broken by means of reducing agents, such treatments resulted in weakened wool fibres. It is found that by using a hydroxy organo-phosphorus compound, in particular tetrakis (hydroxymethyl) phosphonium chloride and a melamine compound having at least one free hydrogen atom or methylol group attached to each of the amino nitrogen atoms, in particular melamine, the cystine and tyrosine content of the wool fibre is substantially reduced and the directional frictional effect of the fibres is appreciably lowered. In particular, it is found that the tetrakis (hydroxymethyl) phosphonium chloride while greatly reducing the cystine content of the wool fibres has little effect on the tyrosine content that a mixture of tetrakis (hydroxymethyl) phosphonium chloride and urea does not have an appreciable effect on either the cystine or tyrosine content of the Wool fibres and that tetrakis (hydroxymethyl) phosphonium chloride and melamine appreciably lowers both the cystine and tyrosine content of the wool fibres and effectively lowers the directional frictional effect producing effective shrink resistance in the wool fibres. At the same time the degradation of the wool fibres due to the action of the tetrakis (hydroxymethyl) phosphonium chloride is maintained at a minimum by the presence of the melamine compound which is believed to form a stable compound, with the phosphorus containing compound in or on the wool fibre.

In addition to improving the shrink resistance vof the wool fibres it is also found that by the process of the present invention the shrinkproofed wool fibres are more receptive to dyestuffs than the untreated wool fibres are more resistant to insects and are also less flammable because of the introduction of phosphorus and nitrogen into the wool fibres in the form of the aforesaid polymer. It has been known to improve the resistance of cellulosic material to burning by the incorporation therein of a polymer containing phosphorus and nitrogen as disclosed in U.S. Pat. No. 3,101,279, issued Aug. 20, 1963, to Hooker Chemical Corporation by impregnating the cellulosic material at room temperature with an aqueous resin solution of tetrakis (alpha-hydroxy organo) phosphonium chloride compound, a water soluble cyclic nitrogen compound selected from triazines and dimethoylol cyclic alkylene ureas, a strong acid salt of magnesium, zinc or a tertiary amine and a sulphide compound capable of combining with an aldehyde whereby polymerization of the phosphonium compound the cyclic nitrogen containing compound and the strong acid salt is effected and thereafter drying and curing the polymer formed the thus impregnated cellulosic material. However, in the process of this patent the impregnation temperature is room temperature which is well below the 40 C. necessary for adequate shrinkproofing according to the present invention and further the hydroxy organo-phosphonium chloride compound is present in the aqueous solution in an amount from l0 to 30% by weight which at temperatures above 40 C. would greatly degrade wool fibres. The polymer formed in the cellulosic fibres is heated to elevated temperatures between and 150 C. for a period from between about 1 and about 10 minutes to effect curing. The process set forth in U.S. Pat. No. 3,101,279 while improving the flame resistance of the wool fibres has little effect on the tendency of the wool fabric to shrink and the reaction effected and the product obtained in the process of this U.S. patent is completely different from that in the process of the present invention.

It is particularly advantageous that in the process of the present invention no high temperature curing is required and further no drying of the fabric is required and the fabric may be passed to the next wet finishing stage directly after the shrinkproofing treatment of the present invention.

It has been further found according to a particularly desirable embodiment of the present invention that the shrinkproofed fibres produced in the aforesaid process can be further treated to enhance their stretch characteristics i.e. impart stretch characteristics to the wool fibres.

In a particularly desirable embodiment of the present invention therefore the shrinkproof wool fibres are aftertreated by subjecting the shrinkproofed Wool fibres to washing with an alkalinesolution at a pH in the range 8 to 12 suitably at a pH in the range 10.0 to 10.5 and desirably for a time varying from 3 hours to 10 minutes at room temperature. The optimum conditions for the aftertreatment are washing for one hour at a pH of about 10 at room temperature. The after-treatment may be carried out at elevated temperature thus reducing the length of time necessary for the after-treatment. As the temperature of the after-treatment is increased the handle and appearance of the fabric becomes less desirable and therefore it is preferable to operate at room temperature. The pH value in the alkaline solution may be obtained by the use of many different solutions including dilute alkaline hydroxide solutions such as aqueous solutions of sodium hydroxide, potassium hydroxide, or calcium hydroxide or alkaline carbonate solutions. A particularly useful solution is a solution containing 0.25% soap and 0.25% sodium carbonate. After the treatment with the alkalinesolution the wool fibres are rinsed and dried.

The after-treatment according to the present invention has the effect of contracting the wool fibres to an elastic condition. That is to say that the percentage contraction of the fibres due to the treatment is the percentage of stretch in the treated fibres. It is essential that the wool fibres treated with the Adilute aqueous alkaline solution have been subjected to the shrinkproofing process of the present invention. It is believed that an important part of any treatment to induce the contraction of wool fibres is the breaking of the cystine disulphide bonds which are very strong covalent bonds and which give appreciable stretch resistance to the wool fibres. The shrinkproofing process as heretofore set forth is believed to effect such rupture of the cystine disulphide bond and thus the shrinkproofed wool fibres, yarns or fabrics can be contractedby breaking of the hydrogen bonds with the alkaline solution and thus contain inherent stretch characteristics.

Stretch fabrics are now widely available in synthetics, cottons and some wool stretch fabrics and these stretch fabrics during the past decade have found wide popularity with the consumer. Several methods are kno-wn for producing stretch wool fabrics. A stretch synthetic yarn may be incorporated in the weave or a core yarn consisting of a wool yarn loosely twisted around a synthetic yarn may be used in the construction. Again by a special process of yarn and fabric construction the natural crimp of wool fibres may be utilized to produce stretch characteristics as in the process known under the trademark Restora. Another process for producing stretchable fabrics is the process known under the trademark Plus-X in which a permanent wave is given to the wool libres while they are in a very crimped state. However, in contrast to the aforesaid relatively complex procedures in the process of the present invention, both the shrinkproofing of the wool fibres and the subsequent after-treatment to impart stretch characteristics thereto may be effected on standard textile machinery and with chemicals already Widely used for textile finishing. Thus with the after-treatment of the present invention the shrinkproofed fibres suitably after washing are subjected to the treatment with an aqueous alkaline solution which causes the libres, fabrics or yarns to contract, usually by an amount of 8 to 12%, and after drying may contain this amount of stretch. Thus fabrics formed from the fibres may be given a two-way stretch both in the warp and weft direction.

According to yet a further embodiment of the present invention the stretch in the fabric produced by the aftertreatment of the shrinkproofed fabric may be set in any desired contour by hot pressing and in this condition may have greater strength than the untreated fabric. A particular use of such a procedure includes the making up of garments in which the fabric may be shaped to a figure and the double radius contours set in place.

The present invention will be further illustrated by way of the following examples in connection with the accompanying drawings in which drawings:

FIG. 1 is a plot of load extension curves of untreated and treated wool fibres;

FIG. 2 is a plot of the super contraction of fibres shrinkproofed according to the process of the present invention subsequently after-treated in aqueous solutions containing 0.25% soap and 0.25% sodium carbonate at 22 C.; and

FIG. 3 is a load extension curve of untreated and treated fabric after-treated for stretch according to the present invention.

In the following examples the following raw materials were used:

Wool fibres Lincoln wool fibres, from which the tips (approximately one-quarter of the fibre) had been removed, were purified by the standard procedure (Richards, H. R. and Speakman, J. B., J. Soc. Dyers Colourists, 7l 537 (1955)), and the fibres, were conditioned at 65% R.H. and 70 F. for at least one week prior to testing.

Wool fabric Worsted flannel, Testfabrics Inc.`8tyle 503A (Plain weave, x 50, 5.3 oz. per sq. yd.) was purified by successive extraction with diethyl ether and ethyl alcohol followed by rinsing in distilled water and then left in distilled water for 24 hours before being rinsed with distilled water several times. After cleaning, the fabric was stored at R.H. and 70 F. before being used for experiments. p

Tetrakis (hydroxymethyl) phosphonium chloride (THPC) Commercial material was purified by recrystallization from alcohol-ether, followed by vacuum drying to give a crystalline product melting at 147-149" C.

Melamine, urea' and other reagents were of analytical .reagent quality.

EXAMPLE I Chemical treatments Duplicate wool specimens (0.849 g. dry weight) were placed in distilled water ml.) in a 250ml. ask for 24 hours. In order to remove air bubbles from the specimens, the fiasks were evacuated and brought to atmospheric pressure alternately until no air bubbles appeared on the fibres during evacuation. The water was then removed and the fibres treated under the various conditions shown in the following Table I. After treatment, the wool was rinsed with copious amounts of distilled water and then placed in distilled water for 24 hours before several further rinses with distilled water. Finally, the specimens were conditioned at 65% RH and 7 0 F. before testing.

Load-extension curves In order to determine the strength and elongation of treated fibres, load-extension curves were obtained, for five randomly chosen fibres from each of the treated specimens, and an Instron Tester Table Model TM. From the load-extension curves, typical examples of which are shown in FIG. 1, various properties were obtained including ibreaking strength, elongation at break, work to break the fibre and the work to stretch the fibre 10, 20 and 30% of its original length. The average values, of these properties, for the five bres shown n Table I.

In addition to the aforesaid treatments, other treatments including those at 65 C. for up to `one hour and at the boil for up to 15 minutes were carried out. However, the treated fibres were extremely soft and had Very little strength. This was also the case for fibres treated TABLE I Work to stretch (g. cmJtex.) Breaking Elongation Time Temp.l stren th at break Treatment (hr.) C.) pH 10% 20% 30% Break (gJtegx.) (percent) Untreated- 6. 82 16. 12 27. 15 34. 46 14. 19 35. 76 0.2% THPC l 72 2 R 4.7 5.37 13. 64 22.28 34. 69 10.07 43.10 0.5% THPC l 72 R 4. 4 5. 62 12. 88 21. 08 32. 26 9. 13 43. 8 1.0% THPC l 72 R 4.0 5.27 12.59 20.18 30.97 8. 65 42.3 2.0% THPC l 72 R 3.7 5.72 12.79 17.43 40.08 8.94 58.5 8.0% THPC l 72 R 3.2 3.80 9.12 14.37 47. 81 5. 91 77.1 1.0 THPC l 0. 25 65 4. 0 5.78 13. 27 21.33 28. 78 9.09 38. 5 0.2 o THPC plus 0.2% urea 72 R 4.9 6.01 13.96 22.28 39.96 10.28 48.3 0.5% THPC plus 0 5% urea l- 72 R 4.5 5. 47 12.58 19. 54 26. 36 8. 04 38. 1 1.0% THPC plus 1.0% urea-. 72 R 4.0 5.36 12.57 20.21 35.01 9. 12 48.3 1.0% THPC plus 1.0% urea l-: 0.25 65 4.0 6.16 13. 58 21.38 30.69 9.07 40.8 0.2 ,J 'IHPC plus 0.2% melamine l 0. 25 65 5. 0 6. 49 15. 12 24. 56 46. 26 12. 0l. 45.3 0.5% THPC plus 0.5% melamine 1 0. 25 65 5. 0 6. 01 14. 17 23. 63 32.38 10. 21 39. 9 1.0% THPC plus 1.0% melamlnel 0.25 65 5.0 5.76 12.82 20.05 42. 03' 8.95 56.8

l Aqueous solution. 2 Room temperature, approximately 22 C.

with more concentrated THPC solutions at elevated temperatures.

From Table I it will be seen that all the treatments reduce the breaking strength of the fibres and increase the elongation at break, but the Work required to break the fibres which is proportional to the area under the load extension curve, is greater for the treated fibres than for the untreated fibres.

Directional-frictional-elect of treated wool fibres To study rapidly the dfe` of treated wool fibres and to compare the results with the dfe of untreated wool fibres, a simple method (Patel, A. B. and Richards, H. R., I. Textile Inst. (1968)) was developed. This consisted of attaching ten (or more) wool fibres to a glass or plastic slide, with the tips at same end. The slide was placed, fibres uppermost, on a tilting table and a small piece of horn placed on the libres. The table was tilted until the horn specimen just slipped and the coefficient of static friction obtained as the tangent of the angle of slip. By connecting a vibrator to the table or gently tapping .the table, the coeicient of dynamic friction was obtained. Results were obtained rapidly by this method and were reproducible. The dfe was calculated (Mercer, E. H. and Makinson, K. R., J. Textile Inst., 38 T 227 (1947)) `from nf=coecient of friction with scale=tan91 n2=coefcient`of friction against scale=tan92 IResults obtained with the treated and untreated wool fibres are shown in Table II.

From the results in Table II, it is obvious that the treatments reduce appreciably the dfe of wool bres on keratin and this is also borne out by the shrinkproong effect of the treatment on wool fabric, reported later. It will be seen that the treatment with aqueous solutions containing THPC and melamine reduces appreciably the dfe and does not drastically affect the strength-elongation properties of the wool bres.

EXAM-PLE II supercontraction of treated wool fibres For imparting stretch characteristics to wool fibres, and hence wool fabrics, the supercontraction of treated wool fibres was investigated. From the practical aspect of treating wool in the mill, it is notpossible to prestretch bres before inducing supercontraction or stretch, and therefore, the bres in the experiments were not prestretched before supercontraction. Also, in order to reduce the number of variables, the experiments were limited to wool bres pretreated with an aqueous solution containing 1% THPC and 1% melamine at 65 C. for 15 min., as this treatment reduced appreciably the dfe and did not drastically affect the load-extension propertes of the wool fibres.

'Wool bres (8 cm. long) were mounted in setting frames and the relaxed bres immersed in the requisite alkaline media. The fibre-length was measured after different time periods and the change in length calculated as a percentage of the initial bre length. In solutions of different alkaline pH values, elevated temperatures caused the treated fibres to supercontract, especially at high alkaline values of pH. In addition, reproducible supercontraction was produced at room temperature if treated fibres were left in solutions of high pH for long periods.-

Fig. 3 shows the supercontraction, with time, of treated fibres in soap plus soda solution (pH 10.7) at room temperature. One of the main differences between fibres supercontracted by a short time at an elevated temperature, and fibres supercontracted for a longer period at room temperature, was the appreciable stretch characteristics of the latter, compared with the more set properties of the former.

EXAMPLE III Wool flannel was given treatments similar to those given to single libres in lExamples I and II, and the fabric properties evaluated. As with single fibres, the most efficient treatment to impart shrink-resistance, without appreciable loss of physical properties is the treatment with an aqueous solution containing THPC and melamine.

Reaction of an aqueous solution containing THPC and melamine with wool fabric TABLE IIL-BREAKING STRENGTH AND ELONGATION FOR WOOL FABRICS Breaking strength Elongation at (lb.) break (percent) pH Warp Weit Warp Weit Untreated 41. 4 33. 2 38. 5 37. 0 Time (min.):

From these results it will be seen that, as with single fibres, the optimum treatment is for 15 min. In all cases except the 60 min. treatment, the work to break the treated specimens is greater than the work required to break the untreated specimens, especially for the 15 min. treatment. Because of these factors, all the following experiments were carried out on Wool fabric treated with an aqueous solution-containing 1% THPC and 1% melamine at 65 C. for 15 min.

Shrinkage of treated wool fabric Specimens (14 in. x 14 in.) of wool fabric both untreated and treated as above were given two washes, each of 20 min. at 22 C., in 0.25% soap plus 0.25% soda. solution (with a liquor ratio of :1) in -a Launderometer and a Washwheel. After each Wash, the fabric was rinsed with ydistilled water and air-dried at onfilter paper, before being conditioned and measured for shrinkage, 'which is given in Table 1V below.

TABLE IV.SHRINK AGE OF TREATED WOOL FABRIC (PERCENT) Launderometer Washwheel Washes Warp Wett Warp Weit Untreated 2 6. 5 8. 4 Treated 2 1. 7 2. 9 Untreated 6 7. 6 8. 7 Treated 6 1. 7 2. 7

It will be seen from the results shown in Table IV that the shrinkage of treated fabric was negligible, compared with the shrinkage of untreated fabric.

Imparting stretch characteristics to treated wool fabric When the above treated wool fabric is washed (0.25% soap plus 0.25% sodium carbonate at 22 C. for 20 min.) for four or more times, it develops stretch characteristics. Alternatively, if the treated fabric is placed in soap-sodium carbonate solution, or other solution of pH 10 or higher, for at least one hour, the fabric shrinks about 10% in each direction and this shrinkage is available for stretch. Load-extension curves were obtained for treated and untreated fabric which had been washed up to twelve times and the results are shown in the following Table V. After four or more washes, the treated fabric specimens show much greater elongation at break than untreated specimens and a relatively smaller decrease in breaking strength. There is an appreciable increase in extension at break of the untreated fabric due to washing which is believed to be lubricating action of the small amount of residual soap left on the fibres.

Elasticity and elastic recovery of treated fabric The slope of the load-extension curve before the yield region gives an indication of the elasticity of the specimens and these values are shown in Table V. For the untreated fabric, the slope is a little greater before washing, again probably due to lubricating action of the traces of soap left on the ibres causing easier yarn slippage in the washed specimens. The treated fabric before Washing has approximately the same slope as the untreated, but washing the treated specimens produces a large decrease in the value of the slope, indicating less elastic recovery for these specimens.

In order to test directly the elasticity and elastic recovery of treated and untreated fabric, specimens (10 in. x l in.) were mounted between clamps and a l lb. weight attached to the lower clamp. Extension of the specimen was determined over a period of one hour, by means of a travelling microscope and, after that time, the weight was removed, the specimen allowed to relax for 24 hrs. The length was then redetermned to give the plastic extension (non-recoverable elongation) after 24 hrs. Results are shown in Table V which also shows the elastic recovery (Morton & Hearle, Physical Properties of Textile Fibers Butterworths, p. 322 (1962)), calculated from:

Elastic recovery (percent) Total extension X 100 Because of the very important role of regain on fabric physical properties, the regain of untreated fabric, treated fabric and treated fabric washed six times, was determined at 65% R.H. and 70 F. The values obtained are shown in Table V, from which it will be seen that the treated fabric has less regain than untreated, but after-treatment to impart stretch increases the regain to that of untreated fabric. It is clear that the ease of Iwettability was much higher for the treated and the stretch fabric than for the untreated fabric.

The treated fabric, which had also been after-treated to give stretch was stretched wet to the near limit and treated in various Ways. Heat alone appeared to have little effect on setting the fabric, even at temperatures high enough to discolor the fabric. However, a hot iron pressed onto the stretched Wet fabric, and held until the fabric was dry, set the specimen in the stretched state. The set specimen also had Very much increased strength, above that for untreated wool fabric.

Dyeing characteristics of treated fabric parisons) of each are as follows:

Acidic 1.0% Kiton Red 2G-Conc. at pH 2.5, obtained with 4% sulphuric acid and 10% Glaubers salt. Specimens entered at 22 C., temperature increased to 60 C. over 10 min. and treated for a further 30 mn. at 60 C.

Basic 1% Galeozine Yellow OX, 3% acetic acid (30%). Specimens entered at 22 C., temperature increased to in l0 min., and treated for a further 30 min. at 50 C.

Direct 1% Chlorantine Fast Green SGLL, 20% common salt. Specimens entered at 22 C., temperature increased to C. over 10 min. and treated a further 30 min. at 60 C.

Reactive 1% Levax Golden Yellow EG at pH 5.5, obtained with 3% acetic acid (30%) and 1.5% ammonium ace- TABLE V.-PROPERTIES OF TREATED AND UNTREATED FABRIC AFTER SE): ERAL WASHES [In 0.25% soap plus 0.25% soda at 22 C. for 20 min.]

Breaking Extension at Extension Extension after Elastic Recovery strength (lb). break (percent) Slope of after unloading (percent) (percent), im-

Number of elastic loading immediate after mediate after Washes Warp Weft Warp Weit region (percent) 24 hr. 24 hr.

Untreated 0(12. 47) l 41. 42 33. 2 38. 5 37. 0 2. 7 15. 2 5. 6 3. 6 63 76 D0 2 41. 4 31. 8 5B. 1 60. 2 2. 5 15. 6 5. 6 3. 6 64 77 42. 4 32. 2 60. 6 60.7 2. 5 15. 6 5. 2 3. 2 66 79 1 Values in brackets are regain at 65% R.H. and 70 F.

As expected from the values of the slopes of the load-extension curves, the extension of the treated fabric increased appreciably with the number of washes. In all cases, the immediate elastic recovery for the treated specimens was appreciably less than that for the untreated specimens. However, the elastic recovery after 24 hrs. of treated specimens, washed up to six times, was virtually the same as that of the untreated fabric, although the initial extension was twice that for the untreated fabric.

tate. Specimens entered at 22 C., temperature increased to 40 C. over 5 min. and treated a further 30 min. at 40 C.

Vat

2.0% Cibanone Brilliant Green BF, reduced in 3% sodium hydrosulphite, 4% ammonium acetate and 20% sulphate. Specimens entered at 22 C. and temperature raised to 50 C. over 10 min. and treated a further 30 min. at 50 C. Developed in 1.5% copper sulphate and sulphuric acid for 30 min. at 50 C.

After each dyeing the specimens were thoroughly rinsed with water and then dried.

During the dyeing, it 'was very apparent that the treated fabric dyed much more rapidly than thc untreated fabric.

The dyed treated fabric appeared to be dyed quite evenly,

and it was easy to obtain even solid shades. Under all the conditions and concentrations used, the treated 4specimens sorbed much more dyestui than the untreated.

Fastncss of dyed treated fabric Table VI, which also contains the fastness ratings according to the Grey Scale. IIn most cases, the light fastness of the dyed treated fabric was greater than that of the dyed untreated fabric. To determine the colorfastness to laundering, dyed specimens of both treated and untreated fabric, were washed Iin I.a Launderometer .and assessed using the Grey Scale (Canadian Government Specifications Board, Schedule 4-GP-2, Canadian Standard Textile Test Methods, Method 19). The results shown in Table VI, indicate that the fastness to laundering of the treated dyed fabric is nearly the same as the fastness of the untreated dyed fabric. Resistance to ab-rasion of untreated fabric, treated fabric, and fabric after'treated for stretch was determined by two methods, Accelerator and Flexing and Abrasion (A.S.T.M., D 1175-64T (1966)). The results obtained, shown in Table VII indicate appreciably more weight loss for the treated specimens, than for-the untreated specimens, in the Accelerator method. In the Flexing and Abrasion method, there appears to be little difference between the untreated and treated specimens but the specimens after-treated for starch ruptured at a much lower value.

TABLE VIL-ABRASION TESTS 0N TREATED AND UN- TREATED FABRIC Flexing and abrasion, number of Accelerator cycles to wel ht Treatment rupture loss gg.)

Untreated 393 8. 3 Treated 348 1 3 Treated and after-treated for stretch. 231 13. 3

I claim:

1. A process of shrinkproong wool which comprises impregnating said wool with an aqueous solution containing a water soluble hydroxy organo-phosphorus compound having the formula (I) CHIOH CHzOH or a phosphorous oxide of a compound of Formula I or (n) CHQON R-P-CHzOH X- CHzOH wherein Ris hydrogen, alkyl or alkenyl and X in Formula II is an anion in a concentration from 0.2 to 2.0% by weight and melamine in a concentration of at least 0.5% by weight at a temperature from about 40 to 80 C. and for a time sufficient to effect the desired shrinkproong and subjecting said treated wool to shrinking with a dilute aqueous alkaline solution at a pH of from 8 to 12 to impart stretch characteristics thereto.

2. A process as claimed in claim 1 in which the organophosphorus compound has the Formula. II.

3. A process as claimed in claim 2 in which X" is bromide, chloride or hydroxyl.

4. A process as claimed in claim 1 in which the organophosphorus compound is tetrakis (hydroxymethyl) phosphonium chloride.

5. A process as claimed in claim 1 in which the organo-phosphorus compound is an oxide of the compound of Formula I.

LIGHT (AT 148 F. BLACK PANEL) AND TO WASHING 0F TREAT- AND UNTREATED FABRIC (GREY SCALE) Fastness to light Carbon arc Xenon lamp Fastness to washing Exposure Dye time (hr.) Untreated Treated Untreated Treated Untreated Treated Acid 0 4 Basic 0 I 1 2 Reactive 0 4-5 Vat 0 4 6. A process as claimed in claim 1 in which the organophosphorus compound is tris (hydroxymethyl) phosphine or an oxide thereof.

7. A process as claimed in claim 1 in which the melamine compound is present in at least the same molar concentration as the organo-phosphorus compound.

8. A process claimed in claim 1 in which the shrinkproofing time is from 48 hours to two minutes.

9. The process as claimed in claim 1 in which in the shrinkproong step the temperature is about 65 C., the time is about 15 minutes and the solutions contain 1% by weight each of tetrakis (hydroxymethyl) phosphonium chloride and melamine.

10. A process as claimed in claim 1 in which the wool is in the form of a fabric.

11. A process as claimed in claim 1 in which the alkaline solution has a pH of between 10.0 and 10.5.

12. A process as claimed in claim 1 in which the shrinking is eiected at room temperature.

14 13. A process as claimed in claim 12 in which the shrinking is effected at room temperature at a pH of about 10 for a period of about 1 hour.

14. A process as claimed in claim 1 in which the 5 alkaline solution is a dilute solution of an alkali metal hydroxide or carbonate.

References Cited UNITED STATES PATENTS 10 2,809,941 10i/1957 Reeves 26o-2 2,810,701 10/1957 Reeves 26o-29.4 3,488,139 1/1970 vuue 8-120 GEORGE F. LESMES, Primary Examiner H. WOLMAN, Assistant Examiner U.S. C1. X.R. 8--128 

